/*
 * Copyright (c) 2014, marco.tamburelli@gmail.com
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: 
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.omorphdb.core.test.mock;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.omorphdb.core.io.Resource;
import org.omorphdb.core.io.ResourceFinder;
import org.omorphdb.core.test.mock.resource.MockResource;

/**
 * It's a factory of {@link ResourceFinder} mocks.
 * 
 * @author Marco Tamburelli
 */
public abstract class ResourceFinderMock implements ResourceFinder
{
	private static final int RESOURCE_SIZE = 4096;
	private static final int PAGE_SIZE = 100;

	private final Map<String, Resource> resourceMap;

	private ResourceFinderMock()
	{
		this.resourceMap = new HashMap<>();
	}

	/**
	 * Creates a basic implementation of a resource finder, which reads and
	 * writes resources on physical hard drive.
	 * 
	 * @return
	 */
	public static ResourceFinder createLocalResourceFinder()
	{
		return new ResourceFinderMock()
		{
			@Override
			Resource openResource(String pathName) throws IOException
			{
				File file = new File(pathName);
				if (file.exists() || file.isFile()) file.delete();

				return Resource.create(file, PAGE_SIZE);
			}
		};
	}

	/**
	 * Creates a basic implementation of a resource finder, which reads and
	 * writes resources on RAM ({@link MockResource})
	 * 
	 * @return
	 */
	public static ResourceFinder createMockResourceFinder()
	{
		return new ResourceFinderMock()
		{
			@Override
			Resource openResource(String pathName) throws IOException
			{
				return new MockResource(RESOURCE_SIZE);
			}
		};
	}

	abstract Resource openResource(String pathName) throws IOException;

	@Override
	public Resource acquire(String name) throws IOException
	{
		String pathName = "TEST_" + name.toUpperCase() + ".txt";

		if (this.resourceMap.containsKey(pathName)) return this.resourceMap.get(pathName);
		else
		{
			Resource resource = openResource(pathName);
			this.resourceMap.put(pathName, resource);

			return resource;
		}
	}

	@Override
	public Resource acquireStorage() throws IOException
	{
		return acquire("storage");
	}

	@Override
	public Resource acquireDefaultIndex() throws IOException
	{
		return acquire("storage.idx");
	}
}
